package com.itheima.reggie.controller;

import com.itheima.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.UUID;

/**
 * 文件上传下载
 *
 * @author solang
 * @date 2022-12-27 10:29
 */
@RestController
@Slf4j
@RequestMapping("/common")
public class CommonController {
    //读取yml配置内容
    @Value("${reggie.path}")//RedisConfig
    private String basePath;

    /**
     * 文件上传
     *
     * @param file
     * @return
     */
    @PostMapping("/upload")
    public R<String> upload(MultipartFile file) {
        //MultipartFile是一个存储在tomcat的临时文件
        log.info("file:" + file.toString());
        //原始文件名
        String originalFilename = file.getOriginalFilename();
        //截取文件后缀
        String substring = originalFilename.substring(originalFilename.lastIndexOf("."));
        //使用UUID重新生成文件名,避免覆盖
        String fileName = UUID.randomUUID().toString() + substring;
        //判断文件是否存在
        File dir = new File(basePath);
        if (!dir.exists()) {
            dir.mkdirs();
        }
        //将临时文件转存储
        try {
            file.transferTo(new File(basePath + fileName));
        } catch (IOException e) {
            e.printStackTrace();
        }
        return R.success(fileName);

    }

    /**
     * 文件下载
     * @param name
     * @param response
     */
    @GetMapping("/download")
    public void download(String name, HttpServletResponse response) {
        try {
            //通过输入流读取响应文件
            FileInputStream inputStream = new FileInputStream(new File(basePath + name));
            //输出流,通过输出流将文件写回浏览器,在浏览器内展示图片
            ServletOutputStream outputStream = response.getOutputStream();
            int len = 0;
            byte[] bytes = new byte[1024];
            while ((len = inputStream.read(bytes)) != -1) {
                outputStream.write(bytes,0,len);
                outputStream.flush();
            }
            inputStream.close();
            outputStream.close();
        } catch (Exception e) {
            e.printStackTrace();
        }

    }
}
